OpenMP* Directives Summary

This is a summary of the OpenMP* directives and clauses supported in the Intel® Fortran Compiler. For detailed information about the OpenMP*API, see the OpenMP Application Program Interface Versions 4.0 and 4.5 specifications, which are available from the OpenMP* web site.

In the directive lists below, an OpenMP directive is qualified with the word Directive when the name of the directive is also used for one or more elements besides the directive. For example: FLUSH refers to a directive, a statement, and a subroutine.

PARALLEL Directive

Use this directive to form a team of threads and execute those threads in parallel.

Directive	Description
PARALLEL Directive (OpenMP*)	Defines a parallel region.

TASKING Directive

Use this directive for deferring execution.

Directive	Description
TASK	Defines a task region.

WORKSHARING Directives

Use these directives to share work among a team of threads.

Directive	Description
DO Directive	Identifies an iterative worksharing construct in which the iterations of the associated loop should be divided among threads in a team.
SECTIONS	Specifies that the enclosed `SECTION` directives define blocks of code to be divided among threads in a team. Each section is executed once by a thread in the team.
SINGLE	Specifies that a block of code is to be executed by only one thread in the team at a time.
WORKSHARE	Divides the work of executing a block of statements or constructs into separate units. It also distributes the work of executing the units to threads of the team so each unit is only executed once.

SYNCHRONIZATION Directives

Use these directives to synchronize between threads.

Directive	Description
ATOMIC	Ensures that a specific memory location is updated atomically; this prevents the possibility of multiple, simultaneous reading and writing of threads.
BARRIER	Synchronizes all the threads in a team. It causes each thread to wait until all of the other threads in the team have reached the barrier.
CRITICAL Directive	Restricts access to a block of code to only one thread at a time.
FLUSH Directive	Identifies synchronization points at which the threads in a team must provide a consistent view of memory.
MASTER	Specifies a block of code to be executed by the master thread of the team.
ORDERED	Specifies a block of code that the threads in a team must execute in the natural order of the loop iterations.
TASKGROUP	Specifies a wait for the completion of all child tasks of the current task and all of their descendant tasks.
TASKWAIT	Specifies a wait on the completion of child tasks generated since the beginning of the current task.
TASKYIELD	Specifies that the current task can be suspended at this point in favor of execution of a different task.

Data Environment Directive

Use this directive to give threads global private data.

Directive	Description
THREADPRIVATE	Specifies named common blocks to be private (local) to each thread; they are global within the thread.

Coprocessor Control Directives

Use these directives to control execution on one or more coprocessors.

Directive	Description
DECLARE TARGET	Specifies named routines and variables that are created or mapped to a device. This directive only applies to Intel® Many Integrated Core Architecture (Intel® MIC Architecture) and Intel® Graphics Technology.
DISTRIBUTE	Specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a teams construct. This directive only applies to Intel® MIC Architecture.
TARGET Directive	Creates a device data environment and executes the construct on the same device. This directive only applies to Intel® MIC Architecture.
TARGET DATA	Creates a device data environment for the extent of the region. This directive only applies to Intel® MIC Architecture.
TARGET ENTER DATA	Specifies that variables are mapped to a device data environment. This directive only applies to Intel® MIC Architecture.
TARGET EXIT DATA	Specifies that variables are unmapped from a device data environment. This directive only applies to Intel® MIC Architecture.
TARGET UPDATE	Makes the list items in the device data environment consistent with their corresponding original list items. This directive only applies to Intel® MIC Architecture.
TEAMS	Creates a league of thread teams inside a target region to execute a structured block in the master thread of each team. This directive only applies to Intel® MIC Architecture.

Vectorization Directives

Use these directives to control execution on vector hardware.

Directive	Description
SIMD Directive (OpenMP*)	Requires and controls SIMD vectorization of loops.
DECLARE SIMD	Generates a SIMD procedure.

Cancellation Constructs

Directive	Description
CANCEL	Requests cancellation of the innermost enclosing region of the construct specified, and causes the encountering implicit or explicit task to proceed to the end of the cancelled construct.
CANCELLATION POINT	Defines a point at which implicit or explicit tasks check to see if cancellation has been requested for the innermost enclosing region of the type specified.

Combined Directives

Use these directives as shortcuts for multiple directives in sequence.

Directive	Description
DISTRIBUTE PARALLEL DO	Specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams.
DISTRIBUTE PARALLEL DO SIMD	Specifies a loop that will be executed in parallel by multiple threads that are members of multiple teams. It will be executed concurrently using SIMD instructions.
DISTRIBUTE SIMD	Specifies a loop that will be distributed across the master threads of the teams region. It will be executed concurrently using SIMD instructions.
DO SIMD	Specifies a loop that can be executed concurrently using SIMD instructions.
PARALLEL DO	Provides an abbreviated way to specify a parallel region containing a single `DO` directive.
PARALLEL DO SIMD	Specifies a parallel region that contains a loop to execute with Single Instruction Multiple Data (SIMD) instructions. Specifies a loop that can be executed concurrently using SIMD instructions. It provides a shortcut for specifying a `PARALLEL` construct containing one SIMD loop construct and no other statement.
PARALLEL SECTIONS	Provides an abbreviated way to specify a parallel region containing a single `SECTIONS` directive. The semantics are identical to explicitly specifying a `PARALLEL` directive immediately followed by a `SECTIONS` directive.
PARALLEL WORKSHARE	Provides an abbreviated way to specify a parallel region containing a single WORKSHARE directive.
TARGET TEAMS	Creates a device data environment and executes the construct on the same device. It also creates a league of thread teams with the master thread in each team executing the structured block. This directive only applies to Intel® MIC Architecture.
TARGET TEAMS DISTRIBUTE	Creates a device data environment and executes the construct on the same device. It also specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a TEAMS construct. This directive only applies to Intel® MIC Architecture.
TARGET TEAMS DISTRIBUTE PARALLEL DO	Creates a device data environment and then executes the construct on that device. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams created by a TEAMS construct. This directive only applies to Intel® MIC Architecture.
TARGET TEAMS DISTRIBUTE PARALLEL DO SIMD	Creates a device data environment and then executes the construct on that device. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams created by a TEAMS construct. The loop will be distributed across the teams, which will be executed concurrently using SIMD instructions. This directive only applies to Intel® MIC Architecture.
TARGET TEAMS DISTRIBUTE SIMD	Creates a device data environment and executes the construct on the same device. It also specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a teams construct. It will be executed concurrently using SIMD instructions. This directive only applies to Intel® MIC Architecture.
TEAMS DISTRIBUTE	Creates a league of thread teams to execute a structured block in the master thread of each team. It also specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a TEAMS construct.
TEAMS DISTRIBUTE PARALLEL DO	Creates a league of thread teams to execute a structured block in the master thread of each team. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams.
TEAMS DISTRIBUTE PARALLEL DO SIMD	Creates a league of thread teams to execute a structured block in the master thread of each team. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams. The loop will be distributed across the master threads of the teams region, which will be executed concurrently using SIMD instructions.
TEAMS DISTRIBUTE SIMD	Creates a league of thread teams to execute the structured block in the master thread of each team. It also specifies a loop that will be distributed across the master threads of the teams.